Any rotating part of a turbomachine must be balanced after manufacture in order to ensure vibration-free operation. Most frequently the procedure is to place counterweights whose weight is determined according to the lack of balance and the distance to the axis of rotation of the machine. If possible, advantage is taken of the bolting of the flanges between two rotating parts to insert the required weights. Thus a counterweight may be slipped onto a fastening bolt between the flange and the clamping nut. An example of this type of assembly is reported in the U.S. Pat. No. 5,285,700. In another case, the rotor comprises a special radial flange for mounting the counterweights. U.S. Pat. No. 4,803,893 describes a device for balancing a turbine rotor according to which a radial groove turned towards the axis of rotation serves as a housing for the counterweights and is made on the rim of the turbine disc.
The applicant company has set itself the objective of perfecting a counterweight mounting means that is independent of any connecting flange between two pieces of a rotating part or of two rotating parts. Specifically, in the context of modular assembly of turbomachines, each rotary module must be supplied perfectly balanced, with no balancing intervention by the person mounting the module onto another module. The mounting of a counterweight by means of connecting flanges is therefore to be avoided.
The balancing device must be as light as possible while being reliable and easy to mount.